README

coinmsg

Message signing for Bitcoin and other cryptocurrencies.

Install

npm install --save coinmsg

Example

var coinmsg  = require('coinmsg'),

    privkey = new Buffer('e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855', 'hex'),
    addr    = '1F3sAm6ZtwLAUnj7d38pGFxtP3RVEvtsbV',
    message = 'Hello, World!'

var sig = coinmsg.sign(privkey, message) // => Buffer

coinmsg.verify(addr, sig, message) // => true

// With other cryptocurrencies:
var coinmsg = require('coinmsg')({
  coinname: 'DOGECOIN',
  curve: 'secp256k1', // optional, defaults to secp256k1
  magicPrefix: '\x19Dogecoin Signed Message:\n'
})

// ... and use coinmsg as above

API

Methods

`sign(privkey, message[, compressed])`

Sign message with privkey and return the signature as a Buffer.

compressed defaults to true.

`verify(address|pubkey, sig, message)`

Verify that sig is valid signature for the message signed by address|pubkey.

sig can be provided as a Buffer or base64 string.

The first argument, address|pubkey, can either be an address provided as a String, or a public key provided as a Buffer.

`format(addr, sig, message)`

Return a "BEGIN BITCOIN SIGNED MESSAGE ..." formatted message.

Other cryptocurrencies

`coinmsg({ coinname: ..., curve: ..., magicPrefix: ... })`

Returns an object with sign(), verify() and format() for the provided options.

curve is optional and defaults to secp256k1

Test

$ git clone https://github.com/cryptocoinjs/coinmsg.git && cd coinmsg
$ npm install && npm test

License

MIT

Credits

Based on the bitcoinjs-lib implementation.

Usage no npm install needed!